Strangeonium spectroscopy at 11 GeV/c and Cherenkov Ring Imaging at the SLD
This thesis is divided into two sections, which describe portions of the data acquisition system and online software for the Cherenkov Ring Imaging Detector (CRID) for the SLD, and analyses of several low cross section strangeonium channels in data from the LASS spectrometer. The CRID section includes a description of the data acquisition system, determination of the preamplifier gain, and development of an online pulse finding algorithm based on deconvolution. Deconvolution uses knowledge of
... uses knowledge of the preamplifier impulse response to aid in pulse finding. The algorithm is fast and shows good single pulse resolution and excellent double pulse resolution in preliminary tests. The strangeonium analyses are based on data from a 4.1 event/nanobarn exposure of the LASS spectrometer in K~p interactions at 11 GeV/c, and include studies of AT|Jt + jr, AKT*, and A0(t». The Ar\n + TC analysis includes a measurement of 8.9±0.6 ubarns for the ATJ' cross section. Production of a 0 (980), seen decaying to rpr", in conjunction with K1385) is confirmed, and the first observation of a 0 (980) production in conjunction with X's of higher mass is presented. Angular analysis of the r\n~ system indicates the possibility of an S-wave in the region of the a 2 (1320). The r|7i"and Ks Kdata from this experiment and similar data from a 4.2 GeV/c Bubble Chamber exposure were fit simultaneously using the coupled channei model of FlattS. The fit yields an T| JE width of 120*^ MeV/c 2 , somewhat higher ii than the 4.2 GeV/c analysis, and a coupling constant ratio g^/g^ of 2.4^,' 7 , somewhat higher than the SU(3) value. The K$K~ data were also fit to a KK molecule model. Both the Flatte and KK molecule models provide a satisfactory fit to the data. The AK"K~" analysis includes both the charged and neutral K*. The total AK'K" cross section is measured to be 3.4±0.2 ubarns. The KK" mass spectrum shows a low mass enhancement, with a mass of 1.950±0.015 GeV/c 2 and a width of 0.25±0.05 GeV/c 2 . A spin-parity analysis this region, assuming the dominance of a single J 1 * 0 , favors \*~, 2~+, or 2 ++ , and strongly disfavors 0" + . The A<| )(t > cross section is measured to be 530±80 nanobarns. Because of low statistics, a spin parity analysis is inconclusive, but disfavors J pc =0~+if the cross section is dominated by a single J PC .